Thismia malipoensis J. D. Ya & W. B. Yu, 2024

Ya, Ji-Dong, Chen, Hai-Yao, Zhang, Wei, Zhu, Ren-Bin, Cai, Jie & Yu, Wen-Bin, 2024, Phylogenetic and biogeographical analyses of Thismia (Thismiaceae) support T. malipoensis as the eighth species in China, Willdenowia 54 (1), pp. 47-63 : 55

Thismia malipoensis J. D. Ya & W. B. Yu , sp. nov.

– Fig. 1–4 .

Holotype: China, Yunnan Province, Wenshan Prefecture, Malipo County, Tianbao Town , 1191 m a.s.l., forest on limestone , 13 Aug 2019, J.-D. Ya & W. Zhang 19CS18569 ( KUN 1584483 !).

Diagnosis — Thismia malipoensis belongs to T. sect. Glaziocharis and can be distinguished from its phylogenetic sister species T. abei by having the annulus of the flower expanded and modified into a cucullate (hood-like) structure with zygomorphic symmetry with one opening on one side. Moreover, T. malipoensis can be distinguished from the morphologically similar T. belumensis , in that the outer and inner tepal appendages are spreading (vs erect) and equal in length by less than 2 cm (vs outer tepal appendage 1.5–2.5 cm and inner tepal appendage c. 3 cm), the inner tepal base is fimbriate at the margin (vs entire) and the inner tepal tip is subulate (vs clavate).

Description — Herbs terrestrial, achlorophyllous, c. 7 cm tall. Roots vermiform, creeping, branched, fleshy, terete, pale brownish. Stems erect, unbranched, 2–4 cm long, densely deflexed papillate hairy. Leaves scale-like, white, translucent, lanceolate, c. 8 × 2 mm, base appressed to stem, apex acuminate. Involucral bracts 3, pale brownish, lanceolate, c. 1 cm long, densely deflexed papillate hairy, base appressed, margin entire, apex acuminate. Pedicel c. 3 mm long (post anthesis). Flowers terminal, solitary, zygomorphic, c. 4.5 × 4 cm (including appendages); hypanthium pyriform, dark green, translucent, c. 8 mm long, c. 7 mm wide near apex, narrowed to c. 4 mm wide just above ovary, outer surface densely deflexed papillate hairy, with 12 raised dark brown longitudinal veins, inner surface smooth; outer tepals 3, pale brown, broadly ovate, c. 2.5 × 3 mm, 2 on opposite side of annulus opening and 1 below annulus opening, outer surface sparsely papillate, apex acute, each outer tepal with a tentacle-like spreading appendage, pale brown, 0.8–1.3 cm × c. 1 mm; inner tepals 3, pale brown, translucent, glabrous, broadly obovate, c. 3.5 × 4 mm, apically broadly fused and tightly adpressed and completely overlapping cucullate part of annulus, each inner tepal with a tentacle-like spreading appendage c. 1.7 cm long, pale brown, fimbriate at basal margin, subulate at apex. Annulus expanded and modified into a cucullate (hood-like) structure, covering apical part of floral tube and forming a lateral floral aperture; cucullate outer surface white with 3 brown lines, glabrous; cucullate inner surface light green, covered with numerous white trichomes. Stamens 6, light yellow, pendent from apical part of floral tube; each connective c. 3.5 mm long, outer surface with 2 linear to filiform thecae, each c. 2 mm long, inner surface smooth, outer surface and apex covered with transparent trichomes; supraconnective apex rounded and curved outward; filaments short, connected to floral tube and annulus. Ovary obovoid, c. 3.5 × 4.8 mm, 1-loculed, with 3 parietal placentae; style c. 0.6 mm long; stigma 3-lobed, lobes triangular-pyramidal, c. 1.2 mm long, apex truncate and densely papillate. Fruit cup-shaped; seeds brown.

Phenology — Observed flowering in August, fruiting in September.

Distribution and habitat — Thismia malipoensis is currently known only from the type locality in Laoshan Provincial Nature Reserve of Malipo County, SE Yunnan. The population consists of about ten individuals under evergreen broad-leaved forest on limestone mountains at an elevation of 1191 m a.s.l. The forest includes the Lithocarpus tephrocarpus (Drake) A. Camus ( Fagaceae ), Alseodaphnopsis andersonii (King ex Hook. f.) H. W. Li & J. Li and Litsea yunnanensis Y. C. Yang & P. H. Huang (both Lauraceae ) and the bamboo Melocalamus arrectus T. P. Yi.

Etymology — The specific epithet “ malipoensis ” refers to the county name Malipo of Wenshan Prefecture, the type locality of the new species.

Chinese name — B 栗坡水玉杯 (má lì pō shuǐ yù bēi).

Conservation status — We evaluated the conservation status of Thismia malipoensis according to the IUCN Red List categories and criteria ( IUCN Standards and Petitions Committee 2022). The new species is known only from the type locality, our field surveys identified only one population with about ten individuals. The conservation status of the species is therefore considered to be Critically Endangered ( CR A2 acd; B1 ab(i,iii,v)+2ab(i,iii,v); C2 a(i); D).

Figures

Fig. 1. Thismia malipoensis – A: plant; B, C: plants in habitat. – Source of material: J.-D. Ya & W. Zhang 19CS18569. – Photographed by J.-D.Ya.

Fig. 2. Thismia malipoensis, different views of flower – A, D: bottom view; B: lateral view; C: top view; E, F: front view. – Source of material: J.-D.Ya & W. Zhang 19CS18569. – Photographed by J.-D. Ya.

Fig. 3. Thismia malipoensis – A: flower, longitudinal section; B: tepals, sparsely papillate outer surface; C–E: floral tube, lateral view (C), top view (D), front view (E); F: stamens, bottom view; G: stamens, lateral view; H: stigma, lateral view; I: stigma, top view; J: ovary, cross-section; K: ovary, longitudinal section. – Source of material: J.-D.Ya & W. Zhang 19CS18569. – Photographed by J.-D. Ya. – All scale bars = 5 mm.

Fig. 4. Thismia malipoensis – A: plant; B: flower, top view; C: flower, longitudinal section; D: stamens, lateral view; E: stamens, bottom view; F: stigma, lateral view; G: ovary, longitudinal section. – Source of material: J.-D.Ya & W.Zhang 19CS18569. – Drawn by Z.-D. Han.